<form id="aLogin" action="<?php echo base_url();?>admin/login/" method="post">
  <span class="row"> 
    <label>Логин</label>
    <input type="text" name="login" placeholder="Введите логин"/>
  </span>
  <span class="row">
    <label>Пароль<label>
        <input type="password"  name="password" placeholder="Введите пароль"/>
  </span>
  <span class="row">
    <input type="submit" value="Войти" />
  </span>
</form>